Qualification
  school              SchoolId --TODO: Ansprechpartner der Schule in Briefe erwähnen
  shorthand           (CI Text)
  name                (CI Text)
  description         StoredMarkup Maybe        -- user-defined large Html, ought to contain full description
  validDuration       Word Maybe                -- qualification is valid for this number of months or indefinitely
  auditDuration       Word Maybe                -- number of month to keep audit log
  refreshWithin       CalendarDiffDays Maybe    -- automatically schedule e-refresher within this number of month/days before expiry
  elearningStart      Bool                      -- automatically schedule e-refresher
  -- elearningOnly       Bool                   -- successful E-learing automatically increases validity. NO!
  -- refreshInvitation   StoredMarkup           -- hard-coded I18N-MSGs used instead, but displayed on qualification page NO!
  -- expiryNotification  StoredMarkup Maybe     -- configurable user-profile-notifcations are used instead NO!
  UniqueSchoolShort school shorthand            -- must be unique per school and shorthand
  UniqueSchoolName  school name                 -- must be unique per school and name
  deriving Generic

-- TODOs:
--  - Enstehen Kosten, wenn Teilnehmer für KnowHow eingereiht werden, aber nicht am Kurs teilnehmen?
--    Falls ja, so sollte bei automatischem refresher vorher der Kunde durch FRADrive befragt werden?!
--    A: Der Inhaber per Email informieren! 
--    A: Es kann gleich eine LMS Pin generiert und verschickt werden!
--  - Aufteilung Qualification "R" in zwei Teile: "R e-learning" und "R praxis" okay? 

-- Fragen an Know-How:
--  - Bedeutung LMS Übermittlung interner Mitarbeiter?
--  - LmsUser shall submit DELTA only: Beware, GET Request will always return the same; until POST Request was processed!
--  - Success/Failure: is an explicit LMS-delete still necessary?
--  - User: pin reset = 1 to existing pin problematic? Resubmission of existing users with pin causes which problems?
--  - ident unique for all qualifications F/R or duplicated? (F/R refreshers might be simultaneous)
--  - Anzahl Fehlversuche: wird pro Durchfallen ein Failed gemeldet oder nur einmal?

QualificationPrecondition
  qualification     QualificationId             -- AND: not unique, ie. qualification can have multiple required preconditions
  required          [QualificationId]           -- OR : alternatives, any one will suffice 
  continuous        Bool                        -- expiring precondition removes qualification
  deriving Generic

-- TODO: connect Qualification with Exams!

QualificationEdit
  user            User
  time            UTCTime
  qualification   QualificationId OnDeleteCascade OnUpdateCascade
  deriving Generic

QualificationUser
  user              User
  qualification     QualificationId OnDeleteCascade OnUpdateCascade
  validUntil        UTCTime
  lastRefresh       UTCTime                     -- lastRefresh > validUntil possible, if Qualification^elearningOnly == False
  firstHeld         UTCTime                     -- first time the qualification was earned, should never change
  -- temporärer Entzug vorsehen
  -- Begründungsfeld vorsehen 
  UniqueQualificationUser qualification user
  deriving Generic

  -- LMS Interface Tables, need regular processing by background jobs, per QualificationId:
  -- 
  -- 1. Daily Job: Add to LmsUser daily all qualification holders with 
  --       0 <= QualificationUserValidUntil - now  < QualificationRefreshWithin  (time to schedule refresher)
  --       /\ now - max(LmsUserStarted) > QualificationRefreshWithin             (not already enlisted; Problem: QualificationELearningOnly!)        
  --    generate fresh ident and pin. (Bools?)
  -- 
  -- 2. REST GET User.csv:
  --     - where LmsUserReceived == Nothing \/ (LmsUserResetPin /\ LmsUserEnded == Nothing)
  --     - delete-flag: isJust LmsUserSuccess
  --   Note: REST means that LmsUserResetPin and LmsUserDelete remain unchanged by this GET request!
  --
  -- 3. REST POST Userlist.csv:   
  --     -- save as is to LmsUserlist
  --     -- change LmsUserEnded from Nothing to Just now, if not included in received list 
  --
  -- 4. REST POST Ergebnisse.csv: just save as is to LmsResult
  --
  -- 5. Daily Job LmsUserlist:               -- Note: containment needs at-once processing
  --     - For all LmsUser:
  --         + if contained, set LmsUserReceived to Just now()
  --         + otherwise,    set LmsUserEnded    to Just now()      
  --     - if LmsUserlistFailed: 
  --         + set LmsUserSuccess to Just False
  --         + set LmsUserDelete  to True 
  --     - move row to LmsAudit
  --
  -- 6. Daily Job LmsResult:
  --     - set LmsUserReceived to Just now()
  --     - set LmsUserSuccess  to Just True
  --     - move row to LmsAudit


LmsUser
  qualification     QualificationId OnDeleteCascade OnUpdateCascade
  user              UserId
  ident             LmsIdent                    -- must be unique accross all LMS courses!
  pin               Text
  resetPin          Bool        default=false   -- should pin be reset?
  success           Bool Maybe                  -- open, success or failure; isJust indicates user will be deleted from LMS 
  -- success        LmsStatus   -- this would also encode Day information?!
  --toDelete encoded by Handler.Utils.LMS.lmsUserToDelete
  started           UTCTime     default=now()
  received          UTCTime Maybe               -- last acknowledgement by LMS 
  ended             UTCTime Maybe               -- ident was deleted from LMS 
  UniqueLmsUser qualification ident
  deriving Generic

-- LmsUserlist stores LMS upload for later processing only 
LmsUserlist
  qualification     QualificationId OnDeleteCascade OnUpdateCascade   
  ident             LmsIdent
  failed            Bool
  timestamp         UTCTime default=now()
  UniqueLmsUserlist qualification ident
  deriving Generic

-- LmsResult stores LMS upload for later processing only 
LmsResult
  qualification     QualificationId OnDeleteCascade OnUpdateCascade
  ident             LmsIdent
  success           Day
  timestamp         UTCTime default=now()
  UniqueLmsResult qualification ident success -- required by DBTable
  deriving Generic

-- Logs all processed rows from LmsUserlist and LmsResult
LmsAudit 
  qualification     QualificationId
  ident             LmsIdent
  notificationType  LmsStatus               -- LmsOpen | LmsBlocked | LmsSuccess Day   
  received          UTCTime                 -- timestamp from LmsUserlist/LmsResult
  processed         UTCTime default=now()
  deriving Generic